1211112111 has 24 divisors (see below), whose sum is σ = 1779995392. Its totient is φ = 731926800.

The previous prime is 1211112103. The next prime is 1211112139. The reversal of 1211112111 is 1112111121.

It is not a de Polignac number, because 1211112111 - 2³ = 1211112103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211112101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128676 + ... + 137766.

Almost surely, 2^1211112111 is an apocalyptic number.

1211112111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1211112111 is a deficient number, since it is larger than the sum of its proper divisors (568883281).

1211112111 is a wasteful number, since it uses less digits than its factorization.

1211112111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9483 (or 9472 counting only the distinct ones).

The product of its digits is 4, while the sum is 12.

The square root of 1211112111 is about 34801.0360621634. The cubic root of 1211112111 is about 1065.9286018049.

Adding to 1211112111 its reverse (1112111121), we get a palindrome (2323223232).

It can be divided in two parts, 12111121 and 11, that multiplied together give a palindrome (133222331).

The spelling of 1211112111 in words is "one billion, two hundred eleven million, one hundred twelve thousand, one hundred eleven".